It will take a pretty forceful rocking back and forth, sort of rotating the table at the same time, pushing up or pulling up. I had the same problem with one of my TT. The bottom of the tubes are usually tapered more than the top. You may have to remove the screws that hold the base to the floor, turn the table upside down on the floor. Now stand on the bottom side of the table at the same time rocking one tube at a time in sort of a circular, pulling up on the tube at the same time. This should free the tubes up at the same time striking the AC circuit breaker, fixing it and the ac will come on (MAYBE)
Serious, this should free up the table legs. Once you have the legs loose from the top. Re-screw just the tubes and bottom flange back to the floor. Repeat the same circular motion, pulling up at the same time. It will take a pretty forceful pulling and circular motion at the same time to free the tubes if sand has got into the taper insert therefore locking the tubes to the flange. Once you have freed the tubes from the flanges, make sure you clean all of the sand from
the tubes and flanges before you reinsert the flanges and tubes back together.